This invention relates to apparatus for mating an exposed photographic film sheet with a photographic print sheet, and for presenting the mated pair of sheets to a photographic processor. The photographic sheets are of the self-developing type. The invention is particularly useful with large format photographic sheets, for example photographic sheets with an eight inch by ten inch format.
The invention is described with specific reference to an embodiment that handles film after exposure to X-rays in a cassette as described in the commonly-assigned patent application of Herman E. Erikson entitled "X-Ray Cassette For Large Format Film", (Ser. No. 841,889) and filed on even date herewith. The disclosure of that application is incorporated herein by this reference. Features of the invention are, however, useful with photographic film other than X-ray film, and are not limited to use with that cassette.
It is commercially common practice with self-developing film to expose a large format photographic sheet in a cassette, to align the exposed sheet in register with a print sheet, and to feed the pair of sheets into the nip between a pair of rollers in a processor. Passage of the sheet through the rollers initiates photographic development of the latent image which the exposed film sheet bears, and fixes the image on the print sheet. The Polaroid Corporation type 8.times.10 Land Film Processor provides this operation with type 808 film and print sheets.
The conventional practice has been to introduce the print sheet to the cassette, and the processor withdraws the aligned sheets from the cassette. One prior practice uses a multi-sheet film assembly that includes both the film and the print sheets for simultaneous loading into the cassette. Another prior practice employs a print sheet which is a separate element from the film sheet and the operator feeds the print sheet into the cassette subsequent to exposure of the film sheet. In both instances, the sheets are selectively positioned within the cassette, which is then presented to the processor. The use of a multi-sheet film assembly lacks flexibility in film selection, is not readily suited for X-ray use, and tends to be more costly than the use of separate sheet elements. The prior use of separate sheets has the disadvantage of requiring that the operator feed the print sheet into the constricted light-tight passage of the cassette. This operation introduces an undue time delay between exposure of the film sheet and processing it. It can also result in the print sheet being wrinkled and even jammed in the cassette passage.
The film cassette which the above-identified concurrently-filed application describes houses a photographic film sheet for X-ray exposure but within a light-tight enclosure for daylight handling. Only a forward tab, a leader and an adjoining lead portion, of the film sheet are outwardly accessible. It is desired to transfer the exposed film sheet from the cassette to a presently-available processor in day-light, i.e., without darkroom protection. As required previously, the transfer is to be in conjunction with a print sheet.
Accordingly, it is an object of this invention to provide improvements in apparatus for positioning an exposed photographic sheet housed in a cassette for transfer from the cassette together with a print sheet, which like the photographic sheet is of the self-developing type, to a photographic processor.
A specific object is to provide positioning apparatus of the above character which readily aligns the cassette-housed film sheet with a print sheet.
Another object of the invention is to provide positioning apparatus of the above character for use with commercially-available processor units without refitting them.
It is another object of the invention to provide positioning apparatus of the above character which maintains the exposed film sheet under light-tight conditions for day-light use.
A further object of the invention is to provide positioning apparatus having the foregoing features which as an optional additional feature, automatically operates film clamping mechanism within the cassette to release the film sheet for ready withdrawal from the cassette and transfer into the processor.
Other objects of the invention will be obvious and will in part be set forth hereinbelow.
With the attainment of these other objects of the invention, a self-developing photographic film of large format can be exposed, either to visible light or to X-rays, whichever the case may be, and immediately processed, all within minutes. The handling of the film and print sheets is minimal and facile, and hence essentially without delay.